Fig. 4.
Tethering experiments on pairs of GUVs. (A) Time-lapse confocal images of GUV pairs (red) in the presence of hGBP1F (green) and GTPγS (Top) (see also Movie S2). Images were analyzed with respect to the fluorescence signal of the protein on the membrane of GUVs (Bottom Left) and contact length between a pair of GUVs (Bottom Right). Experiments were performed in the presence of 2.5 µM of labeled and 20 µM of nonlabeled protein. Arrows indicate time points of nucleotide injections. (B) Same as in A but with GTP (see also Movie S3). (C) Same as in A but with hGBP1NF (see also Movie S4). (Scale bars, 5 µm.) a.u., arbitrary units.